1. Field of Invention
The present application is within the field of threaded fasteners. In particular, this application is in the field of barrel nuts.
2. Background of the Invention
A barrel nut is typified by a segmented cylindrical slug (segmented by a plane that is parallel to the cylindrical axis) with a threaded bore that is perpendicular to the length of the segmented cylinder. See, e.g., U.S. Pat. No. 1,671,757 (issued May 29, 1928) or U.S. Pat. No. 2,809,686 (issued Oct. 15, 1957). Operably, barrel nuts may be employed for fastening together panels, wherein the slug of the barrel nut is positioned inside a cylindrical hole in one panel so that the nut's threaded bore is transverse to the cylindrical hole and aligned with an access hole formed in the other panel. When so positioned inside a cylindrical hole, the barrel nut is captive or self-wrenching so that a bolt can be inserted through the access hole and threaded into the nut. Given said operability, the threaded bore of a barrel nut is frequently configured to float within the segmented cylindrical slug so that some alignment between the threaded bore and the access hole can be achieved after insertion of the nut into the cylindrical hole. Said floating configuration is typically accomplished by loosely providing a nut to a seat formed in the segmented side of the slug. See, e.g., U.S. Pat. Nos. 2,903,035 (issued Sep. 8, 1959), U.S. Pat. No. 2,920,672 (issued Jan. 12, 1960), U.S. Pat. No. 3,081,809 (issued Mar. 19, 1963), U.S. Pat. No. 3,192,982 (issued Jul. 6, 1965), U.S. Pat. No. 3,205,927 (issued Sep. 14, 1965), U.S. Pat. No. 3,322,177 (issued May 30, 1967), U.S. Pat. No. 4,119,130 (issued Oct. 10, 1978), U.S. Pat. No. 4,861,207 (issued Aug. 29, 1989), and U.S. Pat. No. 5,032,047 (issued Jul. 16, 1991). Floating barrel nuts become useless whenever the loose nut disassociates from its seat in the slug. Thus, a need exists for a means for retaining the nut within its seat in the segmented cylindrical slug of a barrel nut.
One approach to retaining a nut in a seat of a segmented cylindrical slug of a barrel nut is shown in U.S. Pat. Nos. 2,903,035; 2,920,672; 3,081,809; 3,192,982; and 3,205,927. In those patents, a nut with a square flange and threaded shaft is seated in the segmented side of the slug via sliding the nut along its flange between a head and foot at either end of the slug in a direction that is parallel to the segment plane. Still referring to those patents, the nut is retained in its seat via placing a small pin through the head and foot at opposite corners of the segment plane so that the nut is confined within the seat via interaction between the pins and the nut's flange or shaft. Although a common means for retaining a nut in the slug of a barrel nut, a pin has not been a satisfactory nut retaining means in many instances because the pin, being secured to the slug at only one of its ends, can be easily bent whereby the pin no longer interacts with the flange or shaft of the nut to retain the nut in its seat. Thus, a need still remains for a more effective means for retaining the nut within its seat in the segmented cylindrical slug.
In view of the foregoing, the pin may be improved as a retaining means by extending each pin across the entire length of the slug so that it is connected at both the head and foot of the slug. Thus far, this has been practically unachievable in view of the NAS 577 standard for barrel nuts. Front views of a NAS 577 barrel nut 1 with a nut 10 and slug 14 is provided as FIGS. 10A and 10B. According to said NAS standard, with reference to FIGS. 10A and 10B, the edge of the cylindrical shaft 11 of the nut 10 corresponds with the edge of the flange 12 so that the extension of the pin 13 across the slug 14 is blocked by the shaft 11 of the nut 10. Referring to FIG. 10A, this blockage cannot be avoided by moving the pins 13 outward (in dashed lines) relative to the nut because, in such a configuration, the nut 10 would not be retained by the pins (see FIG. 10A). Referring to FIG. 10B, the pin location cannot be moved outwardly by extending the flange 12 (in dashed lines) on the sides of the floating nut 10 because such extension would result in the flange 12 protruding beyond the curving surface of the slug 14 whereby the profile of the barrel nut 1 would not be a semi-circle (see FIG. 10B). U.S. Pat. Nos. 5,032,047 and 3,192,982 appear to disclose barrel nut structures that are stabilized via attachment of said structures at both the head and foot of the slug of a barrel nut, but said structures are for purposes of positioning a barrel nut inside the cylindrical hole of a panel and do not serve nut retention purposes beyond the pins described above. As result, a need still remains for a more effective means for retaining the nut within its seat in the segmented cylindrical slug of a barrel nut.